Preheat an air fryer to 200°C for 5 minutes, or preheat the oven to 200°C.
Toss the aubergine with the olive oil, salt and pepper.
Air fry for 10 minutes, shaking halfway through, until golden and tender. Alternatively, roast in the oven for 35 minutes.
Meanwhile, heat a large saucepan over a medium heat and cook the onion until softened.
Add the garlic and cook for 1 minute until fragrant.
Stir in the chopped tomatoes and season well. Simmer for 5 minutes.
Add the Merchant Gourmet Puy Lentils and cook for a further 5 minutes until heated through.
Divide the stew between bowls and top with the roasted aubergine.
Finish with the chopped parsley and serve.